Abstract The Human Sample Core C will be responsible for: 1) collection and preparation of clinical samples and lung specimens; 2) evaluation of vaccine candidates in human primary epithelial cells; and 3) measuring serum RSV antibodies from human and cotton rat samples. It will support and interact with all 4 Projects and the Animal Core B included in this P01. Thus, this Core will serve two main goals. First, it will assure the quality of the human samples, and it will simplify streamlining sample organization, data management and compliance with all regulations. Second, this core will be responsible for: a) running the in vitro primary cell culture assays to evaluate vaccine candidates generated by Projects 1, 2 and 3; and b) measuring serum RSV antibodies in serum samples obtained from infants included in Project 4 and from experimental infections in cotton rats performed in the Animal Core B. This approach will optimize the use of resources and will facilitate integration and synergy among all projects.